Really annoying Minecart noise!

I was in my minecraft superflat world when I all of a sudden heard the sound of a minecart or several minecarts rolling. I looked around the world and the houses I built to follow the noise. It turns out that the noise was coming from one of the houses that I was close to. In that house I built a dining room with a table and six or so chairs that happened to be minecarts. I assumed that the noise was going to go away. But after a few minutes the noise only kept on going. I examined the minecarts real close and they weren't moving. So I broke each minecart and listened again, the rolling noise didn't stop. So I broke the rails that the minecarts were on. I assumed that the noise would stop because the minecarts were gone I had broken them. But the noise didn't go away even though I had everything removed that could make the noise. I then left the world to see if it would do the trick. However as I left the world, and went to the title screen, the noise was suprising still there. I was out of the world, had quit to the title and was starting to get a little angry. Only when I closed the game, was when the noise stopped. I have never experienced that before ever in the years I have been playing this game. If someone could explain what is going on, that would be very much apprieciated. Thank You